Arc Welding Procedure: How to Write, Qualify, and Follow a WPS (Complete Guide)

What Is an Arc Welding Procedure? (And Why Every Weld Needs One)

A shop lands a rush order for a steel spool. The best welder in the building does what he has always done: sets the amps by ear and lays down a bead that looks flawless. Months later, a third-party inspector asks for the WPS and the PQR, and the whole job stalls because nobody can produce them. An arc welding procedure is the thin line between a good-looking weld and a documented, code-accepted one.

In plain language, an arc welding procedure is the written recipe that tells a welder which variables to use so a joint comes out right every single time. The AWS A3.0 standard defines a welding procedure specification as a document that lists the welding variables required to produce a weldment that meets specified requirements. That definition is worth reading twice: the point is not a pretty bead, it is a weld that reliably satisfies an agreed specification.

Procedure Means Repeatable, Not Lucky

Every arc weld is really a stack of decisions. Which process? Which filler? How many amps, which polarity, how fast should the torch or electrode travel, and how hot does the base metal get before the arc even starts? A procedure takes those decisions out of the welder’s head and locks them into controlled ranges and numbers.

At minimum, an arc welding procedure controls:

• Process and current type
• Filler metal classification and diameter
• Amperage and voltage ranges
• Polarity (DCEN, DCEP, or AC)
• Travel speed and number of passes
• Preheat and interpass temperature
• Joint design, welding position, and technique

When those values are written down and followed, two welders on two shifts can produce essentially the same result. That is the whole point of a procedure.

The Arc Welding Family a Procedure Governs

Procedures are written per process, and the five you will meet most often in arc welding are:

Each one has its own essential variables and its own qualification rules, so a procedure for one does not automatically cover another. Building the actual hand skill these procedures assume is a separate job, and our welding practice guide is the natural starting point.

Striking an Arc vs. Documenting a Weld

These two ideas get blurred constantly. Striking an arc is physical: you set the machine, hold the stinger or torch, and manipulate molten metal. It is a craft, and a good welder can make a beautiful weld with nothing but experience and a steady hand.

Documenting a weld is different. It is a paper trail that proves, to an inspector, an engineer, or a client, that the weld will meet a specification every time it is made, by anyone on the crew. ASME Boiler and Pressure Vessel Code Section IX governs the qualification of welding procedures, welders, brazers, and welding operators for ASME Code work, and it is one of several code systems that turn that documentation into a legal requirement. The physical act wins the job. The documented system keeps it.

What This Guide Covers

Over the next sections we will unpack the documents behind a qualified weld (WPS, PQR, and WPQ), the essential variables a procedure actually controls, how each arc process fits in, how to write a WPS step by step, how qualification coupons are tested, which codes apply, and the real benefits and costs of getting it right. We will finish with common mistakes and a practical action plan you can run in your own shop.

WPS, PQR, and WPQ: The Three Documents Behind Every Qualified Weld

Three documents sit behind every weld a code accepts, and welders mix them up constantly. The names all start with W, they live in the same binder, and they all sound official. But each answers a different question, and a shop that cannot keep them straight will stall the moment an inspector asks for paperwork.

Here is the short version.

The WPS Is the Instruction Sheet

The WPS tells a welder how to make a specific joint. It spells out the process, base metal and thickness range, filler metal, joint design, welding position, preheat and interpass temperature, current type, amperage range, polarity, shielding gas, and travel speed. Think of it as the recipe: follow it and the weld should meet the requirements it was qualified for. When polarity is part of the spec, the details matter. The difference between DCEN, DCEP, and AC changes heat balance and penetration, and the WPS fixes which one applies.

The PQR Is the Laboratory Record

A Procedure Qualification Record is the proof behind that recipe. It records the actual welding variables used to produce a test coupon and the results of the mechanical tests performed on that coupon, such as tensile and bend tests. Under ASME Section IX, each WPS must be supported by one or more PQRs, and QW-200.2 requires the PQR to record what the welder actually did: real as-welded values rather than the ranges printed on the WPS. That distinction is why the two documents can never be swapped.

The WPQ Is the Welder’s Record

A Welder Performance Qualification documents that an individual welder can deposit sound welds while following a qualified WPS. The employer tests the welder, usually on a coupon, and records the outcome. It is strictly personal: two welders on the same job each need their own WPQ, even if they weld side by side all day. Qualifications also lapse through disuse. Under ASME Section IX QW-322, a welder’s qualification expires if they have not used that process for six months or more, and AWS D1.1 applies the same six-month rule for requalification. Steady welding practice keeps those skills, and the paperwork, current.

Who Creates and Signs Each Document

The manufacturer or contractor writes the WPS, performs the qualification, and certifies the PQR. The employer, often the same company, qualifies and documents the welder in the WPQ. One person may wear all three hats in a small shop, but the roles stay separate.

The Paper Trail, Start to Finish

1. Select base metal and filler for the joint.
2. Weld a qualification test coupon.
3. Run mechanical tests and record results on the PQR.
4. Write the WPS from the qualified data.
5. Qualify each welder to that WPS.
6. Weld production and keep the records on file.

Why a WPS Without a PQR Is Invalid

A WPS with no supporting PQR is generally invalid. The paper says how to weld, but nothing demonstrates the procedure ever produced a sound, test-passing joint, so an inspector treats it as unqualified and code work stops there. Equally, a welder cannot simply work to an arbitrary WPS their employer never qualified them for. The welder needs a WPQ tied to that specific procedure. The AWS standards library lays out how this qualification chain is structured.

Document Control and Who Holds the Records

Qualified documents are controlled documents. Each carries an identifier and a revision number, and any change to an essential variable forces re-evaluation, often a fresh PQR and a rewritten WPS. Superseded revisions get archived rather than quietly edited, so you can always prove which version a given weld was made to. The manufacturer or contractor keeps the WPS and PQR; the employer keeps the WPQs. All three must be available for inspection on request, which is exactly where the shop in our opening story fell apart.

Essential Variables: What an Arc Welding Procedure Actually Controls

Every line on a WPS exists for a reason: someone proved that changing it changes the weld. The code sorts those lines into three buckets, and once you understand the buckets, the whole document stops looking like boilerplate.

The Three Buckets

• Essential variables: change one and you must requalify, meaning new coupons, new testing, and new paperwork.
• Nonessential variables: documented on the WPS, but they can be adjusted within limits without requalification.
• Supplementary essential variables: dormant unless notch toughness is required. When impact testing is specified, they switch on and behave exactly like essential variables.

From there, the variables fall into recognizable families. Here is how the major ones map out under ASME Section IX.

Not every clause sits in the same bucket for every process. GMAW cares about shielding gas composition; SMAW does not. But the framework is consistent across codes.

Base Metal Grouping

In ASME Section IX, base metals are assigned P-Numbers. Changing from one P-Number group to another is an essential variable for procedure qualification under QW-403. Qualifying on a P-1 carbon steel does not earn you the right to weld P-8 stainless. AWS D1.1 does the same job through its material listings and groupings, published in the AWS standards catalog. The logic: different metallurgy, different behaviour, different proof required.

Filler Metal Classification

Filler metals are grouped by F-Number, which sorts electrodes by usability and operating characteristics. A change in F-Number is essential. Swapping an F4 E7018 for an F1 E6010 is not a harmless substitution; the coating, arc stability, and deposit all shift, so requalification follows. The A-Number tracks deposit chemistry, and a change there matters too.

Thickness, Diameter, and Position

Qualified thickness and diameter ranges come directly from what the PQR coupon proved, including the code’s built-in rules for scaling up or down. A procedure qualified on 6-inch pipe does not automatically transfer to 2-inch tube, and position matters: a weld proven flat may not cover vertical-up or overhead work.

Heat Control

Preheat and interpass temperature are essential when they fall outside the qualified range (QW-406). Post-weld heat treatment changes are covered by QW-407. Both affect cooling rate, hardness, and cracking risk, which is why you cannot quietly skip a stress relief and call the WPS unchanged.

Shielding Gas and Electrical Variables

For GTAW and GMAW, a change in shielding gas composition is an essential variable under QW-408. Going from a 75/25 argon-CO2 blend to pure CO2 is a new procedure, not a tweak. Polarity and current type are equally weighty: flipping from DCEN to DCEP reverses the heat balance, changing penetration and cleaning action, a point we unpack in our guide to TIG welding polarity. Flux-cored work has the same sensitivity, which is why polarity for flux core welding deserves its own attention. Electrode size and, in many codes, wire feed characteristics round out the electrical side.

Technique

Stringer versus weave, pass sequence, and travel speed often sit in the nonessential column. Travel speed, bead width, and cleaning method usually sit here too, giving the welder room to work without voiding the procedure. But when notch toughness is specified, those same technique choices suddenly carry weight, because heat input changes the microstructure.

Why Ranges Must Stay Inside the PQR

Here is the rule that trips up the most shops: the WPS may only promise what the PQR actually demonstrated. If the coupon proved quarter-inch plate, the WPS cannot claim three-quarter-inch coverage just because the welder is confident. An auditor does not compare your weld to a photo of a good bead; they compare the WPS ranges to the PQR ranges line by line. Ranges are evidence, not ambition.

Which Arc Processes Get a Procedure: SMAW, GMAW, FCAW, GTAW, and SAW

Every arc process can be qualified, but each one carries its own essential variables, its own filler-metal groupings, and its own F-numbers. That last detail trips up more shops than any other: a procedure written for one process does not qualify another. Here is how the five workhorses behave when they meet a WPS.

SMAW: The Field and Repair Standard

Shielded metal arc welding remains the most common process for field welding and structural repair. Sticks are portable, the gear is simple, and the arc shrugs off wind, mill scale, and light contamination that would wreck a gas-shielded weld. In procedure terms, filler metals are grouped by F-number under the relevant AWS filler metal specifications, so swapping an E7018 for an E6010 can trigger requalification. Amperage and polarity ranges are logged for every electrode, which is why a chart like our 3/16 E7018 amperage settings is handy on the floor but never a substitute for the qualified range on the WPS.

GMAW: Continuous Wire and High Deposition

Gas metal arc welding feeds wire continuously, giving high deposition rates and a smooth, productive arc. It is also the process most home shops learn first, as our MIG welding at home guide explains. The catch for procedure writers is that shielding gas composition is an essential variable, so switching from a 75/25 argon-CO2 mix to straight CO2 usually means requalifying. Transfer mode (short circuit, globular, or spray) changes the procedure too, and consumables like the contact tip affect consistency weld to weld.

FCAW: Flux-Cored Wire for Structural Work

Flux-cored arc welding uses a tubular wire filled with flux. Electrodes come in two families: self-shielded (gasless), where the flux generates its own shielding, and gas-shielded, which adds an external gas. Self-shielded wire is popular outdoors and in the field, as we cover in our gasless MIG welding guide. Either way, FCAW is a mainstay of structural steel fabrication, and the electrode classification plus shielding gas (if used) belongs on the WPS.

GTAW: Precision and Root Passes

Gas tungsten arc welding trades speed for precision. It is the go-to for root passes on pipe and tubing and for thin, critical work where contamination control matters. Polarity is a critical variable here, since DCEN, DCEP, and AC each change heat balance and cleaning action, and mixing them up can invalidate a procedure. Our TIG welding polarity article breaks down when each mode fits.

SAW: High Deposition for Long, Straight Welds

Submerged arc welding buries the arc under a blanket of granular flux and delivers among the highest deposition rates of any arc process. It suits long, straight, thick-section welds such as pressure vessels, beams, and pipe, and it is frequently automated, as covered in robotic submerged arc welding. Flux type, wire-flux combination, and travel speed are all essential variables.

The takeaway is simple. These five processes each sit in a different place on a WPS, and building skill across them takes deliberate welding practice. But never assume one process’s documents cover another.

How to Write a WPS: A Step-by-Step Method

A WPS is not a creative writing exercise. It is a checklist dressed as a legal document. Follow the same sequence every time and you can build a usable, defensible procedure in an afternoon instead of a week of guessing.

The Eight Steps

1. Read the contract and identify the governing code. The project spec tells you whether you are working to ASME IX, AWS D1.1, API 1104, or an ISO 15614 series. Every later decision flows from that answer, so do not skip it. Read it alongside any addenda, referenced standards, and the owner’s specifications.
2. Pin down the base metals. List the material specification, the P-Number or Group Number, and the thickness range the procedure must cover. Qualified ranges are written as a spread, never a single number.
3. Choose the process and position. SMAW for field stick work, GMAW for speed, FCAW where gasless MIG welding simplifies the job, GTAW where cleanliness matters, SAW for heavy plate. Positions usually start at flat and extend only as far as testing proves.
4. Select the filler metal. Record the classification (E7018, ER70S-6, E71T-1) plus its F-Number and A-Number. These numbers control what you may substitute later without requalifying. The A-Number tracks the chemistry of the deposited weld metal.
5. Decide preheat, interpass, and post-weld heat treatment. Minimum preheat, maximum interpass, and any PWHT cycle belong on the form. Thickness and carbon equivalent set the values.
6. Set the electrical parameters. Amperage, voltage, polarity, electrode or wire diameter, shielding gas mix and flow, and travel speed each get a working range, not one magic number. Our guides to 3/16 E7018 amperage, contact tip care for GMAW, and TIG polarity show how much those ranges move in practice.
7. Confirm the ranges fit an existing PQR. Every range on the WPS must sit inside what the supporting PQR actually tested. If it does not, qualify a new procedure before you write anything down. When the gap is small, the range may already be covered by an overlapping PQR you own.
8. Document, sign, date, and issue. ASME Section IX supplies the forms: QW-482 for the WPS and QW-483 for the PQR. Add a revision number and a controlled distribution list. Issue controlled copies to the shop, the inspector, and the welding supervisor.

Two details trip up first-timers. First, thickness on a WPS is qualified as a spread, so a single coupon can cover a wide band of production work. Second, consumables (gas mix, wire, and tips) are as much a part of the procedure as the amperage. Shops that treat the WPS as a suggestions sheet usually discover the gap at inspection.

The Prequalified Shortcut, and Its Limits

AWS D1.1 lets you skip mechanical testing under Clause 3, but only for prequalified WPSs where base metals, thicknesses, joint details, positions, and processes all fall inside the code’s stated limits. Step outside any one of them and the exemption disappears. Even a prequalified WPS must still be written out, signed, and made available to the welder and the inspector.

Multiple PQRs and Who Signs

One WPS can be supported by more than one PQR. That is common where a shop tests thin coupons and thick coupons separately, then writes a single procedure covering both ranges. Range extension is a paperwork exercise, not a new test, provided the geometry and essential variables match. Whoever holds the engineering responsibility, whether a welding engineer, a qualified supervisor, or the responsible official named in the contract, approves and signs the document.

Then it has to reach the bench. A WPS sitting in an office binder is worthless. The document must be available at the point of use for both the welder and the inspector, and welders should be briefed on it as part of their welding practice routine. A change to a listed variable after qualification requires a new or amended WPS, not a verbal agreement on the floor.

How a Procedure Gets Qualified: PQR Coupons and Mechanical Testing

Qualifying a procedure is a controlled weld job with proof bolted to it. You build a test coupon, weld it exactly as the draft WPS specifies while logging what actually happened, then cut the joint apart and prove it holds. The result is the PQR, the record that backs up the WPS.

Step 1: Build and Weld the Coupon

The code dictates the coupon’s material, thickness, and groove geometry. Fit it up like production work, which is why time spent building real welding skills pays off before qualification day. Then weld it to the letter of the draft WPS while a second person records the actual amps, volts, travel speed, preheat, and pass sequence. Those as-welded values go straight onto the PQR. Deviate from the procedure and the test is void.

Step 2: Visual Inspection

Before anything is cut, the coupon is inspected visually. Undercut, surface porosity, or overlap can send it to the scrap bin — the same defects that sink a production weld sink a coupon, as our guide to overlap welding defects explains. The weld must also satisfy the visual limits written into the WPS itself.

Step 3: Cut and Machine Specimens

The coupon is sectioned and machined into test specimens: tensile bars, guided bend straps, and, when required, Charpy V-notch bars. Specimen preparation is fussy work. A nicked edge or a rough machined face can cause a false failure, so many shops send coupons out to a machine shop.

Step 4: Mechanical Testing

Tensile specimens must reach at least the minimum specified tensile strength of the base metal (QW-153). If a specimen breaks below that number in the weld, the procedure fails.

Guided bend straps are wrapped around a mandrel to stretch the root and face. The coupon passes when it shows no defects exceeding 1/8 in (3 mm) in any direction that are open to the surface — a test of ductility and fusion more than raw strength.

Charpy V-notch testing is not automatic. It is required only when the application specifies impact requirements, and once impact values are on the procedure they become essential variables you cannot casually change. Radiography is used where the code or contract calls for it, confirming internal soundness that a bend test cannot see.

Thickness and Position Ranges

A single coupon qualifies a range of production thicknesses rather than the coupon thickness alone, with the range defined by the code. For ASME work, Section IX lays out those ranges in QW-451: a coupon around 3/8 in thick typically covers a broad band of production work, while very thick or very thin coupons open narrower windows. Position follows the same logic. A coupon welded in the 6G position qualifies the widest range of production positions, whereas a flat-only test restricts you to flat welding.

Who Witnesses and Certifies

On ASME work, an Authorized Inspector employed or approved by the jurisdiction reviews and signs off — the procedure is not qualified until that signature lands. On AWS structural work, the fabricator’s QC department or a designated representative typically witnesses the test, and an accredited lab reports the mechanical results. Whoever signs owns the paperwork.

Procedure Qualification vs. Welder Performance Qualification

Keep the two straight. Procedure qualification proves the recipe works. Welder performance qualification (WPQ) proves the person can follow it. Same coupon geometry, different question, and you need both before a joint is truly covered.

Finally, when a WPS is not prequalified, AWS D1.1 Clause 4 is the structural route: you qualify through testing rather than leaning on the prequalified tables.

The Codes Behind the Procedure: ASME IX, AWS D1.1, ISO, and API 1104

Every WPS you write answers to a rulebook. That rulebook sets what must be tested, which variables are essential, and who may sign off. Pick the wrong one and a perfect weld can still be rejected. Here are the standards governing most arc welding jobs.

ASME BPVC Section IX: The Qualification Standard

ASME Boiler and Pressure Vessel Code, Section IX covers qualification of welding and brazing procedures, welders, brazers, and welding operators. Section IX is a qualification standard, not a fabrication standard. It tells you how to prove a procedure and a person are capable; the rest of the BPVC (Section VIII for vessels, Section I for boilers, B31 codes for piping) tells you how to build and inspect. Read it the wrong way and you will hunt for fabrication rules that are not there.

AWS D1.1/D1.1M: Structural Steel

For welded steel structures and bridges, the governing document is AWS D1.1/D1.1M, Structural Welding Code—Steel. Its practical appeal is the prequalified WPS: stay within the code’s listed base metals, filler metals, joint designs, and ranges, and you can write a WPS without running a PQR at all. Step outside those limits and a qualification test is required. D1.1 also carries detailed clauses on welder qualification, so both halves of “qualified weld” live in one book. The AWS standards catalog lays out the full family, from D1.1 through D1.2 aluminium and D1.6 stainless.

ISO 15614-1 and ISO 9606-1: The International Route

Much of Europe and a large share of the international market runs on ISO. ISO 15614-1 specifies how welding procedures are qualified by test for arc and gas welding of steels and arc welding of nickel and nickel alloys. Its companion, ISO 9606-1, covers qualification testing of welders for fusion welding of steels. Together they mirror the WPS/PQR/WPQ structure, but the variable ranges and test requirements differ, so a procedure qualified to ASME IX does not automatically transfer to an ISO project. If your drawing calls for ISO, follow it from the first coupon.

API 1104: Pipelines

Pipeline work answers to API 1104, which governs the welding of pipelines and related facilities. It carries its own girth-weld qualification rules and acceptance criteria, with a strong field focus. Transmission and distribution crews rarely touch ASME or AWS documents day to day; API 1104 is their rulebook. A consistent girth bead still comes down to fundamentals like travel speed and arc control, the same skills you build in welding practice.

ISO 3834 and EN 1090: The Quality Layer

Above the qualification documents sit quality-system standards. ISO 3834 requires documented welding coordination, including a responsible welding coordinator and controlled procedures. EN 1090 governs the execution of steel and aluminium structures and effectively expects ISO 3834 compliance. That control reaches the shop floor too, from facility planning to fume extraction. Buyers and notified bodies often make these a contract requirement, so a compliant WPS is a starting point, not the finish line.

So Which Code Applies?

You do not get to choose. The answer is already written in the contract documents. Check these in order:

• The drawing and specifications: a note such as “weld per AWS D1.1” or “ASME B31.3” names your rulebook outright.
• The purchase order and contract: quality clauses often add ISO 3834 or EN 1090 on top of the fabrication code.
• The client’s quality manual: owner-operators frequently specify the edition and addenda by year, and the edition matters for qualification.
• Jurisdiction: locally regulated pressure equipment may also trigger OSHA’s welding and cutting requirements, which address safety rather than qualification.

When two documents conflict, the more restrictive requirement normally wins unless the contract says otherwise. Confirm it in writing before you cut a coupon, and note the code, edition, and any addenda on the face of the WPS. That one line prevents more arguments than any test result.

Benefits of a Real Arc Welding Procedure — and the Cost of Skipping One

A procedure is often sold as a compliance chore. That framing misses the real value. In a working shop, a documented arc welding procedure is a business tool: it makes quality repeatable, protects people, and gives you something to show a customer or inspector without scrambling.

The Business Case: Repeatable Quality, Fewer Surprises

When the settings, filler, joint prep, and technique are written down, the outcome stops depending on who happens to be holding the stinger. Two welders on two shifts produce the same joint, which means less rework, less scrap, and more predictable cycle times. That predictability is money. Consistency shows up in appearance too, and the gap between good and bad welds usually traces back to parameters nobody bothered to record.

Documented procedures also reduce rework and make welder training measurable against a fixed, repeatable standard, as opposed to “that looks about right.” A new hire can be checked against the WPS line by line. Onboarding gets faster, and coaching gets objective. If you’re building skills in-house, the approach pairs naturally with welding practice done to a written spec rather than by feel.

The commercial upside is just as concrete: easier customer acceptance, smoother third-party inspection, and a defensible liability position if something ever goes wrong.

Safety Comes From Control

Controlling heat input, current, gas flow, and fume-generating parameters isn’t only about metallurgy. OSHA 1910.252 sets general requirements for welding, cutting, and brazing, covering ventilation, personal protective equipment, and fire prevention, while 1926.351 covers arc welding and cutting in construction and requires protection of personnel, equipment, and surroundings.

The health angle is serious. NIOSH notes that welding fume contains metals such as manganese, hexavalent chromium, and nickel that can harm the nervous system and lungs. OSHA’s permissible exposure limit for hexavalent chromium is 5 micrograms per cubic meter as an 8-hour time-weighted average under 1910.1026.

What Skipping a Procedure Really Costs

• Failed inspections and cut-out of completed welds
• Rework hours, consumable waste, and schedule slip
• Withheld payment until documentation appears
• Lost prequalification and rejected bids on the next project
• In serious cases, structural or pressure failure with legal exposure

Cut-out alone can wipe out the margin on a job, because removal, re-prep, re-weld, and re-inspection all cost more than doing it right the first time. The rush-order scenario at the top of this guide is the mild version. The severe version ends in an incident report.

The Honest Challenges

None of this is free. Qualifying a procedure means paying for coupon prep, testing, and lab time. Maintaining WPSs and PQRs means revision control and the discipline to update them when a variable changes. Some experienced welders resist being told how to weld, especially when their instinct has served them for decades. And qualifications have to be kept current as processes, positions, and personnel change.

Those costs are real, but they are one-time or periodic, and they land on a schedule you control. The costs of skipping a procedure land whenever an inspector, a customer, or an accident decides. Planning a shop that supports all of this is its own project, and our guide to welding facilities walks through layout, ventilation, and equipment choices.

Common Mistakes, Fixes, and Practical Tips for Arc Welding Procedures

Most arc welding procedure failures aren’t metallurgical mysteries. They’re paperwork and discipline problems that surface months later, usually when an inspector is standing in front of the job. Here are the ones we see most often, each paired with a concrete fix. None of them require new equipment, only attention.

Ten Mistakes That Undermine a WPS

1. Ranges wider than the PQR. A WPS range that exceeds the qualified range of its supporting PQR is invalid and can void inspection acceptance of every weld made under it. Fix: build each WPS from the PQR’s actual qualified limits, never from habit.
2. Welders never qualified, or requalified. A flawless WPS is worthless if the person at the torch was never tested to it. Fix: qualify each welder for the process, position, and thickness they actually weld.
3. Lapsed welder qualifications. Under ASME Section IX QW-322, a welder’s qualification expires after six months without welding with that process and must be renewed. Fix: log continuity dates by process; don’t rely on memory.
4. Ignoring interpass temperature and heat input. Heat input, calculated as amperage × voltage × 60 divided by travel speed, becomes a supplementary essential variable when toughness is required. Fix: issue a travel-speed range and a temperature crayon, then spot-check on the floor.
5. Prequalified WPS pushed past code limits. AWS D1.1 limits prequalified WPSs to base metals with a specified minimum yield strength of 100 ksi or less, and to the joint details listed in the code. Fix: confirm grade and joint before claiming prequalification.
6. Missing or out-of-order PWHT. Deferring post-weld heat treatment, or running it in the wrong sequence, leaves stresses the procedure was meant to remove. Fix: write PWHT temperature, rate, and timing into the traveler.
7. No revision control. Any revision to a WPS requires re-approval, and only the current revision should be in use on the shop floor. Fix: pull superseded copies immediately and stamp each revision with a date and approver.
8. Wrong consumable classification or lost traceability. A mismatched filler, or an unreadable lot number, breaks the chain from certificate to finished weld. Fix: match the classification exactly and file certificates by heat number, the same discipline that keeps GMAW contact tips and other consumables in spec.
9. Inadequate preheat on thick or high-carbon steel. Skipping preheat invites cracking, especially in steels that harden readily. See our guide to welding hardened steel. Fix: specify minimum preheat on the WPS and verify it with a contact pyrometer.
10. Documentation that never reaches the welder. A WPS locked in the office binder isn’t a procedure anyone can follow. Fix: post the working revision at the station or attach it to the traveler.

Practical Habits That Keep Procedures Valid

These small routines prevent the failures above.

• Keep a master WPS-to-PQR matrix so every procedure maps to a supporting test record.
• Log welder continuity by process and date, then schedule requalification before the six-month deadline.
• Run mock-up and first-article welds before production. Treat it like training; our welding practice guide explains how to make those reps count.
• Use weld maps and travelers so every joint carries its WPS number and welder ID.
• Hold consumables to their certificates and store filler so lots stay traceable.
• Keep preheat and interpass logs with the traveler so temperature control leaves a paper trail.
• Review procedures annually against the current code edition.

A procedure is only as strong as the habit of following it. Inspectors rarely argue with a shop that can produce the paperwork on demand; they argue with the one that can’t. Treat documents as part of the weld, not an afterthought to it.

Putting It to Work: Your Arc Welding Procedure Action Plan

A procedure is only useful if it exists, stays current, and actually gets followed on the floor. The good news is that compliance isn’t a one-time project—it’s a routine you build. You don’t need a perfect system to start, just a starting point and the discipline to keep it updated. Work this plan in order and you’ll close the documentation gaps that stall jobs months before anyone asks for the paperwork.

The Eight-Step Plan

1. Identify the governing code. Contract documents typically name ASME Section IX, AWS D1.1, ISO 15614, or API 1104 explicitly. Don’t guess and don’t assume. The code defines your essential variables, your qualification tests, and your documentation requirements, so every later decision hangs off this first answer.
2. Inventory what you actually weld. Walk the shop with a clipboard and list the base metals, thickness ranges, joint designs, positions, and processes your work really involves—SMAW, GMAW, FCAW, GTAW, or SAW. Include the odd jobs people forget, like tube fittings and field repairs. That inventory becomes the backbone of your WPS coverage.
3. Audit your existing PQRs. Pull every old procedure qualification record and check whether its qualified ranges still cover today’s work. Thickness, position, and consumable limits are the gaps that bite most often.
4. Write or update your WPSs. Where the code allows a prequalified route, use it and save the testing cost. Where it doesn’t, plan the qualification coupons, mechanical testing, and lab time before the job lands, not after.
5. Qualify every welder who will work. A qualified procedure means nothing without a qualified welder holding it. Test each person to the WPS, log the results, and keep certifications current.
6. Build document control. Three registers do most of the heavy lifting: a WPS register, a PQR register, and a master list mapping each WPS to the PQR or PQRs that support it. Add a welder continuity log to track qualification dates and process continuity, so nothing lapses unintentionally.
7. Train the crew. Walk welders through the procedure that governs their work and explain why each variable matters. When people see that the WPS protects them and the part, they treat it as a tool instead of paperwork. Regular welding practice against the procedure builds that muscle.
8. Audit and revise. Review your whole system annually, and immediately whenever base metals, processes, consumables, or code editions change. A procedure that no longer matches the work is worse than none at all.

Here’s the payoff. A solid arc welding procedure protects three things at once: the weld, the welder, and the business. The weld meets the code because the variables were controlled and tested. The welder is covered because the settings, technique, and safety expectations were documented, not improvised. The business wins because it can walk into any inspection, produce the paperwork, and keep the job moving.

And this matters for careers too. Welders who can read a WPS, follow it, and explain it become the people a shop trusts with the critical work—the pressure joints, the code-stamped welds. Teams that run qualified, documented procedures build a reputation that travels: inspectors remember, customers return, and better projects come looking. Start with one register, one procedure, one conversation on the floor this week. The reputation follows.

Frequently Asked Questions

What is an arc welding procedure?

An arc welding procedure is a controlled, documented set of welding variables—process, filler metal, amperage and polarity ranges, travel speed, preheat, position, and more—that produces a weld meeting a specified requirement. When written out formally it is called a Welding Procedure Specification (WPS). It turns a welder’s individual technique into a repeatable process the whole shop can follow.

What is the difference between a WPS and a PQR?

A WPS tells you how to weld; a PQR is the record proving that procedure actually worked. The PQR documents the variables used to weld a test coupon and the mechanical test results on that coupon. A WPS must be supported by one or more PQRs, and its ranges cannot be wider than what the PQR qualified.

Can I write my own WPS without a testing lab?

You can write a prequalified WPS if your work falls entirely within the limits of a code that offers that route, such as AWS D1.1 Clause 3. For anything outside those limits—unusual base metals, thicker sections, impact requirements—you must qualify the procedure by welding test coupons and having them mechanically tested.

How long does it take to qualify a welding procedure?

A straightforward qualification with tensile and bend tests is often finished in one to three weeks, depending on lab turnaround and whether impact testing is required. Charpy impact testing, radiography, or post-weld heat treatment can add time. Planning the coupon, recording variables accurately, and using a lab familiar with the code speeds things up considerably.

How long does a welder’s qualification stay valid?

Under both ASME Section IX and AWS D1.1, a welder’s qualification typically lapses if the welder has not used that process for six months or more. Written records of continued welding must be maintained to keep qualifications active. Some codes and employers also require periodic requalification regardless of continuity.

Are arc welding procedures required by law, or just by contracts?

For general industry, OSHA sets safety and health requirements for welding but does not mandate a qualified WPS by name. However, structural, pressure, and pipeline codes do require qualified procedures, and contracts on those projects make compliance effectively mandatory. Working to a qualified procedure also provides strong evidence of due diligence if something fails.

Do I need a procedure for MIG and TIG, or only for stick welding?

Every arc process needs a procedure when the code or contract requires one, including GMAW (MIG), FCAW, GTAW (TIG), and SAW. Each process has its own essential variables and filler metal groupings, so a SMAW procedure never covers a MIG operation. Shielding gas composition, for example, is an essential variable unique to the gas-shielded processes.

What happens if I weld production parts without a qualified procedure?

Worst case, the work is rejected outright and must be cut out and redone, delaying payment and damaging your prequalification status. If a weld fails in service, the absence of a qualified procedure and supporting records can expose the shop to liability. In regulated work such as pressure equipment, unqualified welding can also put your certification or stamp at risk.

Authoritative Sources & Further Reading

• https://www.osha.gov/welding-cutting-brazing
• https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.252
• https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.351
• https://www.cdc.gov/niosh/topics/welding/default.html
• https://www.asme.org/codes-standards/find-codes-standards/bpvc-ix-welding-brazing-and-fusing-qualifications
• https://www.aws.org/standards/
• https://www.aws.org/certification/
• https://www.nfpa.org/